Methods and systems for oil leak determination and/or mitigation

ABSTRACT

Methods and systems are provided for a dual function imaging device. In one example, a method may comprise imaging exhaust gas outside of a reverse engine condition via the imaging device. The imaging device may image a surrounding area during the reverse engine condition.

FIELD

The present description relates generally to mitigating oil leaks and/ordetermining a present oil leak via an imaging device.

BACKGROUND/SUMMARY

Vehicle lubrication systems may comprise one or more components forsealing the lubrication system from other systems of a vehicle,including a coolant system, a fuel system, and the like. However, due tovarying pressures of each of these systems in combination with changingengine operating parameters, leaks may occur.

One example of such a leak may include oil leaking from the lubricationsystem into the exhaust gas through one or more of the intake system andcombustion chambers of the engine. Due to the high molecular weight oflubricating oil compared to gasoline and diesel, lubricating oils maydeposit onto waterways and other earthly surfaces rather thandissipating to the atmosphere. While both fuel and oil emissions areundesired, combustion of lubricating oils may present a more immediateenvironmental impact. Furthermore, lubricating oils may be lessflammable than combustion fuels, allowing the lubricating oils to coatsurfaces of an exhaust system and degrade aftertreatment devicesarranged therein.

Other attempts to address oil leaking into combustion components of avehicle include coupling a spectrometer to an exhaust gas outlet of thevehicle. A color of the exhaust gas smoke may be estimated based onfeedback from the spectrometer, wherein the color corresponds to one ormore constituents arranged in the exhaust gas.

However, the inventors herein have recognized potential issues with suchsystems. As one example, oil leaks may degrade a multitude of vehiclecomponents and determination of a leak while visiting a mechanic may betoo infrequent to prevent other vehicle degradations. Alternatively,coupling a spectrometer to the vehicle may be expensive and increasepackaging constraints. Furthermore, the conditions exposed to thespectrometer (e.g., temperature, humidity, airborne particles, etc.) maydegrade the spectrometer, further burdening a vehicle operator.

In one example, the issues described above may be addressed by a methodfor operating a reverse camera outside of a reverse driving condition,capturing one or more images of exhaust gas, and determining an amountof blue in the exhaust gas. In this way, the reverse camera may beutilized outside of a reverse driving condition to determine an oil leakinto combusting systems of the vehicle.

As one example, the reverse camera may be operated during boost andnaturally aspirated engine conditions. The camera may be directed towardone or more tailpipes outside of the reverse condition. The camera maycapture one or more images of the exhaust gas, wherein the images may beintegrated and compared to a wavelength spectrum. A color of the exhaustgas may illustrate a type of system fluid leak. For example, an oilsystem leak into combustion components of the vehicle may generate atleast partially blue exhaust gas. Images captured during naturallyaspirated and boosted conditions may be compared to determine if leaksare occurring during only naturally aspirated conditions, boostedconditions, or both. Based on the determination, engine operatingparameters may be adjusted accordingly and a more accurate estimation ofa location of the leak may be provided to a vehicle service provider.

It should be understood that the summary above is provided to introducein simplified form a selection of concepts that are further described inthe detailed description. It is not meant to identify key or essentialfeatures of the claimed subject matter, the scope of which is defineduniquely by the claims that follow the detailed description.Furthermore, the claimed subject matter is not limited toimplementations that solve any disadvantages noted above or in any partof this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an engine system schematic of a vehicle.

FIG. 2 shows the vehicle propelling visualizing exhaust gas smoke.

FIG. 3 shows a method for visualizing the exhaust gas smoke.

FIG. 4 shows a method for mitigating oil leaks during boostedconditions.

FIG. 5 shows an engine operating sequence illustrating a combination ofthe methods of FIGS. 3 and 4 executed in combination with the enginesystem of FIG. 1.

DETAILED DESCRIPTION

The following description relates to determining and/or mitigating fluidleaks into an engine system. The engine system may be included in ahybrid vehicle, such as the hybrid vehicle of FIG. 1. The engine systemmay further comprise one or more of a turbocharger, intake and exhaustvalves, a crankcase, coolant passages, and the like. The engine systemmay develop one or more leaks, wherein the leak may be determined viaanalyzation of an exhaust gas color. The hybrid vehicle is furtherillustrated in FIG. 2, wherein the hybrid vehicle is shown comprising animaging device. In the example of FIG. 2, the imaging device may be areverse camera. When the vehicle is in a reverse gear, the reversecamera may project an image of a surrounding area adjacent to thevehicle. The surrounding area may be within a reverse threshold range(e.g., between 0.5 to 3 meters away from a rear of the vehicle). Outsideof the reverse gear, the reverse camera may be configured to visualizeexhaust gas. Thus, the reverse camera may focus on an exhaust gasthreshold range (e.g., less than 0.5 meters away from the rear of thevehicle).

A controller of the engine system may comprise instructions stored onnon-transitory memory thereof that when executed enable to controller todirect the reverse camera toward the vehicle tailpipe(s), capture one ormore images of the exhaust gas, and analyze an amount of a specifiedcolor, such as a visible color in the visible light spectrum. In oneparticular example, the visible color includes blue in the exhaust gas.In one example, the wavelength of light may be between 450-495 nm. Inanother example, the visible light of interest may be between 380-450,or 380-495 nm. A filtering lens on the camera may be used that passesvisible light within this spectrum, if desired, or digital filtering toidentify light captured within these wavelengths may be used.

Thus, prior to analyzing the light (e.g., blue in this example), thecontroller may integrate and apply one or more filters to the images. Ifthe amount of blue is greater than a threshold amount of blue, then itmay be determined that oil is leaking into one or more engine systemcomponents. For example, if the number of pixels, each having anintensity of the specified color above a threshold level, is greaterthan a threshold pixel number, an indication of oil leaking may begenerated. Additionally, by visualizing exhaust gas during non-boostedand boosted engine conditions, it may be determined if oil is leakingduring only boosted, non-boosted, or both engine conditions. FIG. 3illustrates a method for visualizing the exhaust gas during boosted andnon-boosted engine conditions and determining if an oil leak is present.

If the oil leak is present, then one or more engine operating parametersmay be adjusted. For example, the imaging device may present a live feedof the exhaust gas onto a screen of an infotainment system.Additionally, an indicator lamp may be activated to indicate to avehicle operator that maintenance is desired. Furthermore, one or moreengine operating parameters may be adjusted to mitigate and/or preventthe oil leak.

Additionally or alternatively, engine operating parameters may beadjusted prior to determination of an oil leak. That is to say, engineoperating parameters may be preemptively adjusted in response to one ormore current engine conditions which may be associated with an oil leak.FIG. 4 illustrates a method for monitoring engine conditions which maybe associated with an oil and adjusting engine operating parameters inresponse to the conditions. Furthermore, the adjustments of FIG. 4 maybe applied in response to the determination of the oil leak during themethod of FIG. 3.

An engine operating sequence illustrating the methods of FIGS. 3 and 4being executed in combination with the engine system of FIG. 1 is shownin FIG. 5.

FIGS. 1-2 show example configurations with relative positioning of thevarious components. If shown directly contacting each other, or directlycoupled, then such elements may be referred to as directly contacting ordirectly coupled, respectively, at least in one example. Similarly,elements shown contiguous or adjacent to one another may be contiguousor adjacent to each other, respectively, at least in one example. As anexample, components laying in face-sharing contact with each other maybe referred to as in face-sharing contact. As another example, elementspositioned apart from each other with only a space there-between and noother components may be referred to as such, in at least one example. Asyet another example, elements shown above/below one another, at oppositesides to one another, or to the left/right of one another may bereferred to as such, relative to one another. Further, as shown in thefigures, a topmost element or point of element may be referred to as a“top” of the component and a bottommost element or point of the elementmay be referred to as a “bottom” of the component, in at least oneexample. As used herein, top/bottom, upper/lower, above/below, may berelative to a vertical axis of the figures and used to describepositioning of elements of the figures relative to one another. As such,elements shown above other elements are positioned vertically above theother elements, in one example. As yet another example, shapes of theelements depicted within the figures may be referred to as having thoseshapes (e.g., such as being circular, straight, planar, curved, rounded,chamfered, angled, or the like). Further, elements shown intersectingone another may be referred to as intersecting elements or intersectingone another, in at least one example. Further still, an element shownwithin another element or shown outside of another element may bereferred as such, in one example. It will be appreciated that one ormore components referred to as being “substantially similar and/oridentical” differ from one another according to manufacturing tolerances(e.g., within 1-5% deviation).

FIG. 1 depicts an example of a cylinder of internal combustion engine 10included by engine system 7 of vehicle 5. Engine 10 may be controlled atleast partially by a control system including controller 12 and by inputfrom a vehicle operator 130 via an input device 132. In this example,input device 132 includes an accelerator pedal and a pedal positionsensor 134 for generating a proportional pedal position signal PP.Cylinder 14 (which may be referred to herein as a combustion chamber) ofengine 10 may include combustion chamber walls 136 with piston 138positioned therein. Piston 138 may be coupled to crankshaft 140 so thatreciprocating motion of the piston is translated into rotational motionof the crankshaft. Crankshaft 140 may be coupled to at least one drivewheel of the passenger vehicle via a transmission system. Further, astarter motor (not shown) may be coupled to crankshaft 140 via aflywheel to enable a starting operation of engine 10.

One or more portions of the crankshaft 140 may be lubricated via oilhoused in a crankcase 82. The crankcase 82 may be sized such that thecrankshaft 140 may be actuated according to a full oscillation of thepiston (e.g., from TDC to BDC or vice-versa). The crankcase 82 may befurther coupled to a lubrication system of the engine. Thus, oil orother lubricants may enter and depart the crankcase 82. A sensor 84 maybe configured to monitor a condition of the crankcase 82 and providefeedback to the controller 12. The sensor 84 may be configured tomonitor one or more of a pressure, temperature, humidity, and the like.Herein, the sensor 84 is a pressure sensor.

Cylinder 14 can receive intake air via a series of intake air passages142, 144, and 146. Intake air passage 146 can communicate with othercylinders of engine 10 in addition to cylinder 14. FIG. 1 shows engine10 configured with a turbocharger 175 including a compressor 174arranged between intake passages 142 and 144, and an exhaust turbine 176arranged along exhaust passage 148. Compressor 174 may be at leastpartially powered by exhaust turbine 176 via a shaft 180. A throttle 162including a throttle plate 164 may be provided along an intake passageof the engine for varying the flow rate and/or pressure of intake airprovided to the engine cylinders. For example, throttle 162 may bepositioned downstream of compressor 174 as shown in FIG. 1, oralternatively may be provided upstream of compressor 174.

Exhaust passage 148 can receive exhaust gases from other cylinders ofengine 10 in addition to cylinder 14. Exhaust gas sensor 128 is showncoupled to exhaust passage 148 upstream of emission control device 178.Sensor 128 may be selected from among various suitable sensors forproviding an indication of exhaust gas air/fuel ratio such as a linearoxygen sensor or UEGO (universal or wide-range exhaust gas oxygen), atwo-state oxygen sensor or EGO (as depicted), a HEGO (heated EGO), aNOx, HC, or CO sensor, for example. Emission control device 178 may be athree way catalyst (TWC), NOx trap, various other emission controldevices, or combinations thereof.

An exhaust tuning valve 172 may be arranged between the turbine 176 andthe emission control device 178. The exhaust tuning valve 172 may beactuated to adjust exhaust backpressure. For example, the exhaust tuningvalve 172 may be configured to partially obstruct the exhaust passage148 such that less exhaust gas may flow past the exhaust tuning valve172. The exhaust tuning valve 172 may be actuated to more closedpositions to increasingly obstruct the exhaust passage 148. In turn,this may increase the exhaust backpressure, which may decrease alikelihood of oil leaking from the crankcase 82.

Each cylinder of engine 10 may include one or more intake valves and oneor more exhaust valves. For example, cylinder 14 is shown including atleast one intake poppet valve 150 and at least one exhaust poppet valve156 located at an upper region of cylinder 14. In some examples, eachcylinder of engine 10, including cylinder 14, may include at least twointake poppet valves and at least two exhaust poppet valves located atan upper region of the cylinder.

Intake valve 150 may be controlled by controller 12 via actuator 152.Similarly, exhaust valve 156 may be controlled by controller 12 viaactuator 154. During some conditions, controller 12 may vary the signalsprovided to actuators 152 and 154 to control the opening and closing ofthe respective intake and exhaust valves. The position of intake valve150 and exhaust valve 156 may be determined by respective valve positionsensors (not shown). The valve actuators may be of the electric valveactuation type or cam actuation type, or a combination thereof. Theintake and exhaust valve timing may be controlled concurrently or any ofa possibility of variable intake cam timing, variable exhaust camtiming, dual independent variable cam timing or fixed cam timing may beused. Each cam actuation system may include one or more cams and mayutilize one or more of cam profile switching (CPS), variable cam timing(VCT), variable valve timing (VVT) and/or variable valve lift (VVL)systems that may be operated by controller 12 to vary valve operation.For example, cylinder 14 may alternatively include an intake valvecontrolled via electric valve actuation and an exhaust valve controlledvia cam actuation including CPS and/or VCT. In other examples, theintake and exhaust valves may be controlled by a common valve actuatoror actuation system, or a variable valve timing actuator or actuationsystem.

Cylinder 14 can have a compression ratio, which is the ratio of volumeswhen piston 138 is at bottom center to top center. In one example, thecompression ratio is in the range of 9:1 to 10:1. However, in someexamples where different fuels are used, the compression ratio may beincreased. This may happen, for example, when higher octane fuels orfuels with higher latent enthalpy of vaporization are used. Thecompression ratio may also be increased if direct injection is used dueto its effect on engine knock.

Lubricated portions of the engine system 7 may include the turbocharger175, the intake valve 150, the exhaust valve 156, and the crankshaft140. Each of these components may be prone to degradation, wherein thedegradation may include an oil leakage. For example, compressor bearingsmay be lubricated to mitigate metal on metal contact. However, due tohigh rotation speeds of the compressor (e.g., 20,000revolutions-per-minute), the oil may get foamy. If the oil remains foamyupon return to an oil reservoir, then a pump may be unable to flow theoil to the compressor bearing. This may result in metal on metalcontact, which may lead to a crack or hole. This may leak oil upon afuture lubrication of the compressor bearing, thereby leading to oilflowing to the cylinder 14.

As another example, the crankcase 82 may flow oil into the cylinder 14during some engine operating conditions. For example, if a crankcasepressure is within a threshold pressure of a current exhaust gaspressure, then oil from the crankcase 82 may flow past the piston 138and into the cylinder 14. The crankcase pressure may be estimated basedon feedback from the sensor 84 to the controller 12. To prevent oilflowing from the crankcase 82 to the cylinder 14, one or more engineoperating parameters may be adjusted to increase an exhaust gastemperature and/or decrease the crankcase pressure.

In some examples, each cylinder of engine 10 may include a spark plug192 for initiating combustion. Ignition system 190 can provide anignition spark to cylinder 14 via spark plug 192 in response to sparkadvance signal SA from controller 12, under select operating modes.However, in some embodiments, spark plug 192 may be omitted, such aswhere engine 10 may initiate combustion by auto-ignition or by injectionof fuel as may be the case with some diesel engines.

In some examples, each cylinder of engine 10 may be configured with oneor more fuel injectors for providing fuel thereto. As a non-limitingexample, cylinder 14 is shown including two fuel injectors 166 and 170.Fuel injectors 166 and 170 may be configured to deliver fuel receivedfrom fuel system 8. Fuel system 8 may include one or more fuel tanks,fuel pumps, and fuel rails. Fuel injector 166 is shown coupled directlyto cylinder 14 for injecting fuel directly therein in proportion to thepulse width of signal FPW-1 received from controller 12 via electronicdriver 168. In this manner, fuel injector 166 provides what is known asdirect injection (hereafter referred to as “DI”) of fuel into combustioncylinder 14. While FIG. 1 shows injector 166 positioned to one side ofcylinder 14, it may alternatively be located overhead of the piston,such as near the position of spark plug 192. Such a position may improvemixing and combustion when operating the engine with an alcohol-basedfuel due to the lower volatility of some alcohol-based fuels.Alternatively, the injector may be located overhead and near the intakevalve to improve mixing. Fuel may be delivered to fuel injector 166 froma fuel tank of fuel system 8 via a high pressure fuel pump, and a fuelrail. Further, the fuel tank may have a pressure transducer providing asignal to controller 12.

Fuel injector 170 is shown arranged in intake passage 146, rather thanin cylinder 14, in a configuration that provides what is known as portfuel injection (hereafter referred to as “PFI”) into the intake portupstream of cylinder 14. Fuel injector 170 may inject fuel, receivedfrom fuel system 8, in proportion to the pulse width of signal FPW-2received from controller 12 via electronic driver 171. Note that asingle driver 168 or 171 may be used for both fuel injection systems, ormultiple drivers, for example driver 168 for fuel injector 166 anddriver 171 for fuel injector 170, may be used, as depicted.

Controller 12 is shown in FIG. 1 as a microcomputer, includingmicroprocessor unit 106, input/output ports 108, an electronic storagemedium for executable programs and calibration values shown asnon-transitory read only memory chip 110 in this particular example forstoring executable instructions, random access memory 112, keep alivememory 114, and a data bus. Controller 12 may receive various signalsfrom sensors coupled to engine 10, in addition to those signalspreviously discussed, including measurement of inducted mass air flow(MAF) from mass air flow sensor 122; engine coolant temperature (ECT)from temperature sensor 116 coupled to cooling sleeve 118; a profileignition pickup signal (PIP) from Hall effect sensor 120 (or other type)coupled to crankshaft 140; throttle position (TP) from a throttleposition sensor; and absolute manifold pressure signal (MAP) from sensor124. Engine speed signal, RPM, may be generated by controller 12 fromsignal PIP. Manifold pressure signal MAP from a manifold pressure sensormay be used to provide an indication of vacuum, or pressure, in theintake manifold. Controller 12 may infer an engine temperature based onan engine coolant temperature.

As described above, FIG. 1 shows only one cylinder of a multi-cylinderengine. As such, each cylinder may similarly include its own set ofintake/exhaust valves, fuel injector(s), spark plug, etc. It will beappreciated that engine 10 may include any suitable number of cylinders,including 2, 3, 4, 5, 6, 8, 10, 12, or more cylinders. Further, each ofthese cylinders can include some or all of the various componentsdescribed and depicted by FIG. 1 with reference to cylinder 14.

In some examples, vehicle 5 may be a hybrid vehicle with multiplesources of torque available to one or more vehicle wheels 55. In otherexamples, vehicle 5 is a conventional vehicle with only an engine. Inthe example shown, vehicle 5 includes engine 10 and an electric machine52. Electric machine 52 may be a motor or a motor/generator. Crankshaft140 of engine 10 and electric machine 52 are connected via atransmission 54 to vehicle wheels 55 when one or more clutches 56 areengaged. In the depicted example, a first clutch 56 is provided betweencrankshaft 140 and electric machine 52, and a second clutch 56 isprovided between electric machine 52 and transmission 54. Controller 12may send a signal to an actuator of each clutch 56 to engage ordisengage the clutch, so as to connect or disconnect crankshaft 140 fromelectric machine 52 and the components connected thereto, and/or connector disconnect electric machine 52 from transmission 54 and thecomponents connected thereto. Transmission 54 may be a gearbox, aplanetary gear system, or another type of transmission. The powertrainmay be configured in various manners including as a parallel, a series,or a series-parallel hybrid vehicle.

Electric machine 52 receives electrical power from an energy storagedevice 58 (herein, battery 58) to provide torque to vehicle wheels 55.Electric machine 52 may also be operated as a generator to provideelectrical power to charge battery 58, for example during a brakingoperation. In some examples, the electric machine 52 may be coupled tothe turbine 176, as will be described in greater detail below.

The controller 12 receives signals from the various sensors of FIG. 1and employs the various actuators of FIG. 1 to adjust engine operationbased on the received signals and instructions stored on a memory of thecontroller. For example, adjusting engine operating parameters mayinclude adjusting an actuator of the exhaust valve 156, an actuator ofthe spark plug 192, and an actuator of the fuel injector 166 in responseto feedback from the sensor 84.

Turning now to FIG. 2, it shows an embodiment 200 of the vehicle 5. Assuch, components previously introduced may be similarly numbered insubsequent figures. The vehicle 5 is shown having its wheels 55 arrangedon a ground. The vehicle 5 may comprise one or more of an infotainmentsystem, a navigation system, and an entertainment system arranged withina vehicle cabin where vehicle occupants may reside.

An axis system 290 is shown comprising two axes, namely an x-axisparallel to a horizontal direction and a y-axis parallel to a verticaldirection. A direction of vehicle movement 292 may be substantiallyparallel to the x-axis. Specifically, the direction of vehicle movement292 illustrates a forward direction of vehicle movement. The forwarddirection may be achieved when the vehicle is in a “drive” gear. Thedrive gear may include a vehicle transmission being in a first gear orhigher. Thus, the drive gear may not be in a reverse gear when thevehicle 5 is moving in the forward direction 292. As an example, thevehicle 5 may move in a direction opposite the forward direction 292when the vehicle 5 is in a reverse gear.

The vehicle 5 may emit exhaust gas 212 through one or more tailpipes 214when an engine (e.g., engine 10 of FIG. 1) is combusting. An image ofthe exhaust gas 212 may be captured by an imaging device 216. Theimaging device 216 may be a camera and/or video recorder arranged on arear of the vehicle. The imaging device 216 may be one or more of areverse camera, blind-spot camera, and bird's eye view camera. Thebird's eye view camera may include a plurality of cameras configured tocapture a 360° image of the vehicle such that an overhead view of thevehicle may be provided to a vehicle operator. In this way, the imagingdevice 216 may be a single camera of the plurality of cameras arrangedon a rear of the vehicle 5. At any rate, the imaging device 216 may be acamera arranged on a rear of the vehicle 5, wherein the camera maycomprise a function other than imaging exhaust gas 212. In someexamples, the imaging device 216 may be an imaging device solely devotedto imaging exhaust gas and may not provide any other function.

Herein, the imaging device 216 is a reverse camera, wherein the camerais configured to capture a surrounding area adjacent the vehicle 5. Morespecifically, the imaging device 216 may capture a first surroundingarea when the vehicle 5 is in a reverse gear. The first surrounding areamay comprise an area within 0.5 to 4 meters away from the rear end ofthe vehicle 5. As such, the tailpipe(s) 214 and exhaust gas 212 may notbe included in the image of the first surrounding area. Outside of thereverse condition, the imaging device 216 may capture a secondsurrounding area, wherein the second surrounding area may comprise anarea less than 0.5 meters away from the rear end of the vehicle 5. Thus,the tailpipe(s) 214 and the exhaust gas 212 may be included in thesecond surrounding area. Outside of the reverse driving condition alsorefers to a non-reverse driving condition.

In some examples, a number of imaging devices 216 may be equal to anumber of tailpipes 214. Thus, if there are two tailpipes 214, thenthere may be two imaging devices 216. In some examples, there may beonly one imaging device of the imaging devices 216. The one imagingdevice may be able to visualize exhaust gas being emitted from each ofthe tailpipes 214. As such, the one imaging device may be arranged in alocation between the tailpipes 214. In some examples, the imagingdevices 216 may be arranged at a rear bumper, adjacent a license plate,adjacent a rear door, and/or adjacent one or more taillights. The reardoor may be a door which provides access to a vehicle trunk or to avehicle engine, depending on a layout of the vehicle (e.g., frontengined or rear engine, respectively). For a vehicle with the engineadjacent its front wheels, the rear door may open to a trunk, where thevehicle operator may store one or more items.

The imaging device 216 may comprise one or more features configured toassist the imaging device 216 to capture an image of the exhaust gas 212with increased quality. These features may include one or more of aservomotor, infrared, and light. For example, the servomotor may allowthe imaging device 216 to rotate, thereby increasing an imaging range ofthe imaging device 216. In this way, the imaging device 216 may not befixed, but rather, may be able to rotate around and within a 360° plane.In some examples, additionally or alternatively, the imaging device 216may comprise infrared features such that the imaging device 216 maycapture images during nighttime. This may be beneficial during instanceswhere the taillights are not bright enough or when the taillights arenot illuminating a desired area. In this way, the imaging device 216 maynot be reliant on the taillights to capture a quality image, wherein thequality image may sufficiently focus on exhaust gas. This may includedetermining that a color saturation of an image will be greater than athreshold quality, which may be based on a non-zero value. If the colorsaturation is less than the threshold quality, then the infrared may beactivated and/or the camera may be actuated by a controller signal to anactuator of the servomotor to actuate the camera. In one example, thethreshold quality is based on a confidence factor calculated based onimages captured by the imaging device 216 compared to images captured bya camera and/or video that is not coupled to the vehicle 5.

The imaging device 216 may capture images of the exhaust gas 212 duringsome engine operating parameters. As an example, the imaging device 216may capture images of the exhaust gas during engine conditions outsideof a reverse condition. This may include engine stops, idle, low load,high load, and the like. Thus, the imaging device 216 may function as areverse camera during a reverse operation of the vehicle 5, whileoperating as an exhaust gas visualization device during other engineoperating conditions. In this way, the imaging device 216 may beconfigured to display an image of a surroundings of the vehicle 5 or animage of the exhaust gas 212 to a screen in the vehicle 5. The screenmay be included in a navigation system and/or infotainment system of thevehicle 5, wherein the screen is arranged in the vehicle cabin for thevehicle occupants to see. Additionally or alternatively, the image maybe sent to a mobile device belonging to the vehicle operator.

The image of the exhaust gas 212 may be captured by the imaging device216, wherein the image may be processed via routine stored innon-transitory memory of a controller (e.g., controller 12 of FIG. 1).The routine, such as the method of FIG. 3, may apply one or more filtersto the image to determine a color of the exhaust gas 212. Based on adetermined color, the routine may be able to diagnose one or more leaksof engine components, if any. As an example, if the exhaust gascomprises a threshold amount of blue, then oil may be leaking throughone or more of a valve seal, a piston ring, and/or a turbo seal.Additionally, a time at which the exhaust gas is imaged may becharacteristic of certain types of leaks. Continuing with the exampleabove, if a threshold amount of blue is in the exhaust gas during anengine start, then it may be determined that oil is leaking through thevalve seal. However, if the exhaust gas is blue outside of the enginestart and not during the engine start, then it may be determined thatoil is leaking past the piston ring. As another example, if exhaust gascomprises a threshold amount of white, then coolant may be leaking intothe combustion chamber via one or more of a head gasket, cylinder head,and engine block. A method for capturing images of the exhaust gas,along with determining its color will be described below.

Turning now to FIG. 3, it shows a method 300 for capturing exhaust gasimages via an imaging device and determining a color of the exhaust gas.Instructions for carrying out method 300 and the rest of the methodsincluded herein may be executed by a controller based on instructionsstored on a memory of the controller and in conjunction with signalsreceived from sensors of the engine system, such as the sensorsdescribed above with reference to FIG. 1. The controller may employengine actuators of the engine system to adjust engine operation,according to the methods described below.

As an example, the method 300 may be implemented using the variouscomponents described above with respect to FIGS. 1 and 2. Specifically,the method 300 may utilize the imaging device 216 of FIG. 2. The imagingdevice 216 may capture one or more images of exhaust gas, wherein thecontroller may apply one or more filters to the captured images todetermine a color of the exhaust gas, if any, based on the method 300.It will be appreciated that the method 300 may also be implemented withvehicle system other than the embodiments of FIGS. 1 and 2.

The method 300 begins at 302, which includes determining, estimating,and/or measuring current engine operating parameters. Current engineoperating parameters may include, but are not limited to, one or more ofthrottle position, engine temperature, engine speed, manifold pressure,vehicle speed, exhaust gas recirculation flow rate, and air/fuel ratio.

The method 300 may proceed to 304, which may include determining if thevehicle is in reverse. The vehicle may be in reverse if a reverse gearis selected and/or if the vehicle is moving in a reverse direction(e.g., opposite the forward direction of vehicle movement 292 of FIG.2). If the vehicle is in a reverse gear and/or is moving in a reversedirection, then the method 300 may proceed to 306, which may includedirecting the imaging device to visualize a first surrounding areabehind the vehicle. The surrounding area behind the vehicle may includean area adjacent a rear of the vehicle (e.g., between 1 to 5 meters).This may further include where the imaging device does not captureimages of the exhaust gas and/or exhaust tailpipes.

The method 300 may proceed to 308, which may include displaying animaging device feed onto a screen of an infotainment system in a vehiclecabin. As such, a live feed of the imaging device may be projected ontothe screen of the infotainment system to a vehicle operator, wherein thelive feed includes the first surrounding area.

The method 300 may proceed to 310, which may include continuing toprovide the imaging device feed until the vehicle is adjusted out of thereverse gear. This may include shifting from the reverse gear to a drivegear, neutral, park, or the like.

Returning to 304, if the vehicle is no longer in reverse and is in adifferent gear (e.g., drive, neutral, or park), then the method 300 mayproceed to 312, which may include directing the rear imaging devicetoward tailpipe(s). Thus, the imaging device may visualize a secondsurrounding area, closer to the vehicle than the first surrounding area.This may include adjusting a position of the imaging device and/oradjusting a focus of the imaging device. As an example, the imagingdevice may be actuated to visualize an area within the thresholddistance of the rear of the vehicle. This may include actuating theimaging device such that one or more tailpipes of the rear may bevisible within a range of the imaging device. Additionally oralternatively, one or more setting of the imaging device may be adjustedsuch that the focus is changed. This may include adjusting one or moreof an aperture, shutter speed, ISO, exposure, zoom, and the like. Forexample, by increasing the ISO, the imaging device is more sensitive tolight. As another example, increasing the aperture may increase aproximal focus. That is to say, by increasing the aperture, objectscloser to the imaging device may be in greater focus than objectsfarther from the imaging device.

In some examples, additionally or alternatively, the vehicle may be anautonomous vehicle, wherein the vehicle may independently adjust itsposition to increase a quality of an image captured of the secondsurrounding area. This may include the vehicle actuating in forward,reverse, and/or angular (e.g., turning) directions to increase the imagequality. The image quality may be dependent on sun light, wind, andother weather conditions. In this way, the vehicle may independentlyadjust its position to improve image quality of the second surroundingarea without vehicle operator inputs.

The method 300 may proceed to 314, which may include capturing a firstexhaust gas image during a first engine condition. The first enginecondition may be a non-boosted engine condition or a boosted enginecondition. The non-boosted engine condition may include a naturallyaspirated engine condition where boost air from a compressor does notflow to the engine. Thus, the boosted engine condition may include anengine condition where boost air from the compressor does flow to theengine. This may include a snapshot or a video clip. The snapshot may bea still-image. The video clip may be a video of the exhaust gas, whereinthe video may be for a threshold duration (e.g., 1 to 10 seconds). Inone example, the video clip is exactly three seconds long. In someexamples, additionally or alternatively, the first exhaust gas image mayinclude a plurality of images captured rapidly over a short period oftime (e.g., one to two seconds). Herein, the first engine condition is anon-boosted engine condition.

The method 300 may proceed to 316, which may capturing a second exhaustgas image during a second engine condition. The second engine conditionmay be unequal to the first engine condition such that if the firstengine condition is a non-boosted engine condition, then the secondengine condition is a boosted engine condition. Herein, the secondengine condition is a boosted engine condition. Additionally oralternatively, the method may prioritize capturing exhaust gas images ofthe second engine condition under high boost conditions (e.g., hardtip-in).

The method 300 may proceed to 318, which may include determining a colorof each of the first and second images. Prior to determining the colorof the images, the images may be transformed via a first or secondtransformation.

The first transformation may include converting the first exhaust gasimage and the second exhaust gas image into first and second frequencydomains via fast Fourier transform (FFT). The first and second frequencydomains may be passed through a frequency corresponding to a color blue.In one example, the frequency corresponding to the color blue may be arange spanning 606 to 668 terahertz (THz). First and second amplitudesmay be associated with the first and second frequency domains, the firstand second amplitudes corresponding to an amount of blue in each of thefirst and second exhaust gas images, respectively. In some examples, anyamount of blue may be associated with an oil leak. In other examples,additionally or alternatively, the first and second amplitudes may becompared to a threshold amplitude, wherein the threshold amplitudecorresponds to an amount of blue in exhaust gas produced from oil beingpresent in exhaust gas. As such, if the first and/or second amplitudesare greater than or equal to the threshold amplitude, then an oil leakmay be present. The threshold amplitude may be empirically determinedvia analyzing exhaust gas with some amount of oil therein, wherein theamount of oil corresponds to an average amount of oil occurring duringan oil leak.

The second transformation may include integrating the first and secondexhaust gas images over time by using a match filter. The match filtermay compare the first and second exhaust gas images to previouslyobtained exhaust gas image comprising known amounts of blue smoke. Ablue smoke amplitude of the first exhaust gas image may be compared to ablue smoke amplitude of the second exhaust gas image. As describedabove, the first exhaust gas image may be captured during a non-boostedengine condition and the second exhaust gas image may be captured duringa boosted engine condition. Thus, if the blue smoke amplitudes of thefirst exhaust gas image and the second exhaust gas image aresubstantially similar, then a degradation may be present where engineoil is leaking into the exhaust gas during non-boost and boosted engineconditions. This may include oil leaking past a valve or piston seal.However, if the blue smoke amplitudes of the first exhaust gas image andthe second exhaust gas image are unequal. As an example, if the bluesmoke amplitude of the second exhaust gas image is greater than the bluesmoke amplitude of the first exhaust gas image, then oil may be leakingduring only boosted conditions. This may indicate a turbo sealdegradation.

In some examples, the integrating may include a differential imagecomparator filter technique operated on each pixel of the capturedimage. The differential image comparator filter may identify a change inthe blue and/or white smoke color being added onto an image capturedprior to the acceleration from a stop. In some examples, a comparisonbetween exhaust gas from a stopped idling vehicle and an accelerationfrom a stop of the same vehicle may demonstrate a greatest shift inexhaust gas color. That is to say, the acceleration away from a stoppedidling vehicle may produce an amount of smoke due to oil burning in theexhaust.

Thus, the method may include capturing an image at a stop, prior to anacceleration, (e.g., a base image) and compare it to an image capturedas the vehicle accelerates from the stop (e.g., an acceleration image).The acceleration image may first be adjusted to a same image footprintas a camera distance changes with the vehicle movement. That is to say,the base image may comprise a constant image footprint, while theacceleration image may experience a changing image footprint as thecamera distance increases with vehicle movement. Following adjusting ofthe image footprint of the acceleration image, the base image may beremoved from the acceleration image, thereby leaving a pixelcontribution of the exhaust gas from only the acceleration. That is tosay, a base exhaust color may be filtered out of the acceleration imageto allow only the exhaust gas color produced in response to theacceleration to remain in the acceleration image. The intensity of thesmoke can then be determined by integrating the pixels red, green, andblue (RGB) contributions, in a specified range, and comparing these torespective intensity thresholds. This comparison to the “base image”method may be repeated throughout the vehicle acceleration, as the smoketends to increase as the vehicle accelerates. Once the acceleration iscomplete, an amount of blue in the exhaust gas smoke may be estimated.

Additionally or alternatively, each image pixel may comprise threeintensity values for each of the RGB contributions. The desired colorcombination ranges of RGB may be specified prior to an accelerationand/or vehicle start and the differential image may be filtered to passthrough only the desired color combination ranges. The intensityintegration may operate on this color filtered image representation.However, it will be appreciated that the intensity values may not beanalyzed until the base image is filtered out of the acceleration image.

The method 300 may proceed to 320, which may include determining if bothimages comprise blue. This may be determined by comparing blueamplitudes of the first exhaust gas image and the second exhaust gasimage to the threshold amplitude. If amplitudes of both the firstexhaust gas image and the second exhaust gas image are greater than thethreshold amplitude, then it may be determined that both images compriseblue and the method 300 may proceed to 322, which may include indicatingan oil leak is occurring during both the first and second engineconditions. The indicating may include activating an indicator lampalerting a vehicle operator that vehicle maintenance is desired.

The method 300 may proceed to 324, which may include adjusting engineoperating parameters during the non-boosted and boosted engineconditions in response to the engine leak. As an example, the adjustingmay include adjusting one or more of a compression ratio of the enginecylinders, an engine power output, a fuel injection volume and timing,boost, exhaust valve timing, spark timing, and an intake air flow. Forexample, oil leaking into the combustion chambers may decrease acompression of the engine cylinders, thus, it may be desired to increasethe compression ratio of the engine cylinders in response to the oilleak. Additionally or alternatively, engine power output may bedecreased in response to the oil leak, wherein decreasing the enginepower output may include decreasing the fuel injection volume and/ordecreasing the intake air flow (e.g., moving the throttle to a moreclosed position). As such, the controller may signal to an actuator tomove the throttle to a more closed position, such that intake air flowdecreases. Additionally, the controller may signal to an actuator of thefuel injector to inject less fuel.

Returning to 320, if a blue amplitude of one or more of the first andsecond exhaust gas images is not greater than or equal to the thresholdamplitude, then both the first and second exhaust gas images do notcomprise blue. The method 300 may proceed to 326 to determine if thefirst exhaust gas image comprises blue. The first exhaust gas image maycomprise blue if the blue amplitude of the first exhaust gas image isgreater than or equal to the threshold amplitude. If the blue amplitudeof the first exhaust gas image is greater than the threshold amplitude,then oil may be leaking during non-boosted engine conditions.

The method 300 may proceed to 328 to indicate that oil is leaking duringonly the first condition. As a result, oil may not be leaking from aturbo seal. As an example, oil may be leaking from the crankcase to thecombustion chamber. Additionally or alternatively, oil may be leakingpast a valve seal. The indicating may further include activating anindicator lamp, the indicator lamp expressing a vehicle maintenance isdesired.

The method 300 may proceed to 330, which may include adjusting engineoperating parameters during only the first engine condition (e.g., thenon-boosted engine conditions). The adjustments may include adjustingone or more of a piston oscillating range, an exhaust valve timing, andspark timing.

Additionally or alternatively, the exhaust valve timing may be delayedto increase an exhaust gas pressure. More specifically, it may bedesired to increase the exhaust gas pressure to a pressure at leastgreater than a crankcase pressure by a threshold pressure. The thresholdpressure may be greater than 0.5 kPa. In one example, the thresholdpressure is exactly 2.0 kPa. As such, it may be desired that the exhaustgas pressure be at least greater than the crankcase pressure by 2.0 kPa.The delaying of the exhaust valve timing may be based on a differencebetween the crankcase pressure and the exhaust gas pressure, wherein asthe difference decreases, the exhaust valve timing may be increasinglydelayed. By delaying the exhaust valve timing, the exhaust pressure mayincrease, thereby decreasing a likelihood of oil flowing from thecrankcase to the combustion chamber. Additionally or alternatively, thespark timing may be retarded such that combustion may be delayed. Theretarded spark timing may further include retarding an intake valveopening to prevent blow through gases from the intake manifold directlyinto the exhaust passage.

As another example, adjusting the piston oscillating range may includedecreasing the range in which the piston may oscillate such that adistance between top-dead center (TDC) and bottom dead center (BDC) maybe reduced. By decreasing the range of the piston, less blow-by gasesmay flow to the crankcase and a crankcase pressure may becorrespondingly reduced, thereby decreasing oil leaking from thecrankcase to the combustion chamber. As such, based on current engineoperating parameters, it may be desired to either increase exhaust gaspressure or decrease crankcase pressure. For example, it may bedifficult to sufficiently increase exhaust gas pressure outside of boostconditions, as such, it may be desired to decrease crankcase pressuresby decrease blow-by gas flow to the crankcase.

Returning to 326, if the blue amplitude of the first exhaust gas imageis less than the threshold amplitude, then an oil leak may not bepresent during non-boosted engine conditions. The method 300 may proceedto 332, which may include determining if the second exhaust gas imagecomprises blue. If the blue amplitude of the second exhaust gas image isgreater than or equal to the threshold amplitude, then an oil leak maybe present during boosted engine conditions.

The method 300 may proceed to 334 to indicate an oil leak during onlythe second condition. As such, the oil leak is associated with boostedconditions, and therefore may indicate a degradation of a turbo seal.The indicating may include activating an indicator lamp therebyexpressing to a vehicle operator that vehicle maintenance is desired.

The method 300 may proceed to 336 to adjust engine operating parametersduring only the second engine condition. The adjusting may includeadjusting boost. Adjusting boost may include adjusting an opening of awastegate. For example, the controller may determine a control signal tosend to a wastegate actuator. The opening may be dependent on amagnitude of the oil leak, wherein the magnitude increases as adifference between the blue amplitude and the threshold amplitudeincreases. As the magnitude increases, the wastegate opening may alsoincrease. In some examples, the turbo may be completely deactivated suchthat boost no longer flow to the engine.

Returning to 332, if the blue amplitude of the second exhaust gas imageis less than the threshold amplitude, then the method 300 may proceed to338, which may include determining that no oil leak is present. As such,the oil may not be leaking during each of the first and second engineconditions. The method 300 may proceed to 340, which may includemaintaining current engine operating parameters and does not adjustengine operating parameters in response to an oil leak.

Turning now to FIG. 4, a method 400 for mitigating oil leaks during oneor more engine operating conditions. The controller (e.g., controller12) may signal to one or more actuators of various engine systemcomponents to adjust an operation of the component such that in cylinderpressures may increase to mitigate oil leak from a crankcase intoexhaust gas flow.

The method 400 begins at 402, which includes determining current engineoperating parameters. The current operating parameters may includeengine temperature, engine speed, manifold pressure, throttle position,boost pressure, exhaust gas pressure, EGR flow rate, and air/fuel ratio.

The method 400 may proceed to 404, which may include determining if anexhaust gas pressure is greater than a crankcase pressure. The exhaustgas pressure may be determined based on feedback from a pressure sensor,arranged in an exhaust passage between an engine and a turbine, to thecontroller. Similarly, the crankcase pressure may be determined based onfeedback from a pressure sensor arranged in the crankcase. Additionallyor alternatively, one or more of the exhaust gas pressure and crankcasepressure may be estimated based on one or more engine operatingconditions. A look-up table comprising multiple inputs, including boostpressure, engine speed, spark timing, exhaust valve timing, and fuelinjection timing. Additionally, the crankcase pressure may be trackedover time based on pressure increases and decreases due to pistonoscillations, blow-by gases, and positive crankcase valve (PCV)openings. If the crankcase pressure is greater than exhaust gaspressure, then oil may leak from the crankcase to the combustionchamber, which may generate blue exhaust gas smoke and lead to enginedegradation. The engine degradation due to oil leak may include crackingand the like. If the exhaust gas pressure is greater than the crankcasepressure, then the method 400 may proceed to 406 to maintain currentengine operating parameters. In this way, an oil leak may not occurunder the current engine operating parameters.

If the exhaust gas pressure is not greater than the crankcase pressureby at least the threshold pressure, then the method 400 may proceed to408, which may include adjusting one or more engine operatingparameters. The one or more engine operating parameters may includeadjusting an exhaust valve opening at 410, adjusting spark timing at412, adjusting a wastegate position at 414, and adjusting an exhausttuning valve position at 416.

Adjusting the exhaust valve opening at 410 may include adjusting theexhaust valve opening such that the exhaust valve opening is retarded.An exhaust gas pressure may increase in response to the retarded exhaustvalve opening, thereby decreasing a likelihood of oil leaking from thecrankcase to the exhaust passage. A magnitude of the retarding may bebased on a current exhaust pressure and the crankcase pressure. Forexample, if the crankcase pressure is less than the current exhaustpressure by at least the threshold pressure (e.g., 2 kPa or 0.02 atm),then the exhaust valve opening timing may not be adjusted. However, ifthe current exhaust gas pressure is not greater than the crankcasepressure by the threshold pressure, then the exhaust valve opening maybe retarded. In such an example, the exhaust valve opening may beincreasingly retarded as the crankcase pressure approaches the currentexhaust pressure. For example, the exhaust valve opening may be moreretarded in response to a difference between the current exhaustpressure and the crankcase pressure being 0.5 kPa compared to adifference being 1.0 kPa. Additionally or alternatively, spark may besimilarly retarded such that spark timing is more retarded as thedifference between the current exhaust pressure and the crankcasepressure decreases toward zero.

In some examples, the controller may make a logical determination (e.g.,regarding a position of an actuator of the exhaust valve) based on logicrules that are a function of exhaust pressure, cylinder pressure, pistonposition, and cam position. The controller may then generate a controlsignal that is sent to the exhaust valve actuator.

Additionally or alternatively, positions of a wastegate and compressorbypass valve (CBV) may be adjusted. The wastegate may be configured tobypass exhaust gas around a turbine. In this way, if the wastegate isadjusted to a more closed position, then exhaust pressure may increase.The CBV may be moved to a more open position, thereby allowing moreintake air to bypass the compressor such that a current turbo speed(e.g., amount of boost) is maintained. A magnitude of the wastegateclosure may be based on a difference between the current exhaustpressure and the crankcase pressure. As the difference decreases and thecrankcase pressure approaches the current exhaust pressure, thewastegate may be moved to an increasingly closed position such that lessexhaust gas may bypass the turbine, forcing more exhaust gas to flowthrough the turbine.

Additionally or alternatively, an exhaust tuning valve (ETV) may beadjusted to adjust exhaust gas pressure. In one example, the ETV may beused substantially similarly to exhaust tuning valve 172 of FIG. 1. TheETV may increase exhaust gas pressure by moving to a more closedposition such that a constriction of an exhaust passage is increased. Amagnitude of the closure of the ETV may be based on the differencebetween the current exhaust gas pressure and the crankcase pressure.Similar to the retardation of the exhaust valve opening, a magnitude ofthe closure of the ETV may increase as the difference between thecurrent exhaust gas pressure and the crankcase pressure decreases. Inthis way, a cross-sectional flow through area of the exhaust passage maydecrease.

At any rate, by adjusting one or more of the exhaust valve timing, sparktiming, wastegate, and ETV, the exhaust gas pressure may be increased.The method 400 may proceed to 418, which may include determining if thecurrent exhaust pressure is greater than the crankcase pressure. Thismay include determining if the exhaust gas pressure is greater than thecrankcase pressure by at least the threshold pressure.

If the current exhaust pressure is not greater than the crankcasepressure by at least the threshold pressure, then the method 400 mayproceed to 420, which may include adjusting engine operating parametersto a greater degree. For example, this may include further delaying theexhaust valve opening, retarding spark more, moving the wastegate to amore closed position, and moving the ETV to a more closed positioncompared to the adjustments at 410, 412, 414, and 416, respectively.

If the current exhaust pressure is greater than the crankcase pressureby the threshold pressure, then the method 400 may proceed to 422 tomaintain current engine operating parameters. In this way, a magnitudeof the exhaust operating parameter adjustments are not increased.

It will be appreciated that the methods of FIGS. 3 and 4 may be operatedin tandem or individually. Additionally or alternatively, theadjustments described method 400 may be executed during method 300 inresponse to the determination of an oil leak being present.

Turning now to FIG. 5, it shows an engine operating sequence 500illustrating the vehicle 5 executing methods 300 and 400 of FIGS. 3 and4. Plot 505 illustrates if a vehicle is reversing, plot 510 illustratesif an exhaust gas color is blue, plot 515 illustrates if boost isactive, plot 520 illustrates a crankcase pressure, large dash line 522illustrates an exhaust gas pressure and small dash line 524 illustratesa threshold pressure, where large dashes are bigger than small dashes,plot 525 illustrates a spark timing, plot 530 illustrates a wastegateposition, plot 535 illustrates an exhaust tuning valve (ETV) position,plot 540 illustrates an exhaust valve timing, and plot 545 illustratesan indicator lamp activity. The open and closed positions illustrated inthe engine operating sequence 500 illustrate fully open and fully closedpositions, respectively. The fully open position may correspond to avalve position where maximum fluid flow is allowed. Thus, the fullyclosed position may correspond to a valve position where fluid flow isprevented or a minimum fluid flow is allowed. A more open position mayrefer to a position that is closer to the fully open position than aprevious position from which it moved. Time increases from a left to aright side of the figure.

Prior to t1, the vehicle is reversing (plot 505). As such, the imagingdevice may be visualizing a surrounding area behind the rear of thevehicle and may be unable to visualize the exhaust gas. Thus, it may beunknown if the exhaust gas is blue (plot 510). Boost is not active whilethe vehicle is reversing (plot 515) in the example of FIG. 5. Thecrankcase pressure is increasing (plot 520), as is the exhaust gaspressure (plot 522). The threshold pressure (524) may be less than andtrack the exhaust gas pressure. As such, the threshold pressure may be afixed value representing a pressure less than the exhaust gas pressureby a minimum amount. In one example, the threshold pressure is less thanthe exhaust gas pressure by exactly 2.0 kPa. Spark timing may be betweenadvanced and retarded (plot 525). The wastegate position may be fullyopen (plot 530) due to boost not being active. An ETV position may befully open (plot 535). An exhaust valve timing may be between advanceand retarded (plot 540). An indicator lamp may be off (plot 545).

At t1, the vehicle is no longer reversing and may be switched to adifferent gear. In this example, the vehicle may be switched to a drivegear. Between t1 and t2, the imaging device is direct to visualizeexhaust gas smoke. The images of exhaust gas smoke captured by theimaging device may be analyzed similar to the analyzation describedabove with respect to method 400 of FIG. 4. In the present example, theexhaust gas does not have a threshold amount of blue color. As such, oilmay not be leaking. Furthermore, boost may not be active. As such, itmay be determined that oil may not be leaking during non-boost engineconditions (e.g., naturally aspirated conditions).

At t2, boost may be activated and the wastegate may move to a moreclosed position to direct at least some exhaust gas to the turbine.Between t2 and t3, the imaging device may visualize the exhaust gasduring the boost engine conditions to determine if oil is leaking. Asshown, the exhaust gas does not have a threshold amount of blue. Thus,it may be determined that both boosted and non-boost engine conditionsare not leaking oil. The imaging device may continue to visualizeexhaust gas while the vehicle is not reversing.

At t3, boost is no longer active. The exhaust gas pressure begins todecrease, however, the crankcase pressure remains relatively constant.Between t3 and t4, the crankcase pressure exceeds the threshold pressuresuch that the difference between the crankcase pressure and the exhaustgas pressure is less than 2.0 kPa. This may increase a likelihood of oilleaking from the crankcase to the exhaust gas. In response to thedifference between the exhaust gas and the crankcase pressure being lessthan the threshold pressure, one or more engine operating parameters maybe adjusted at t4. Specifically, to increase the exhaust gas pressure,spark timing is more retarded, the ETV position is more closed, and theexhaust valve timing may be more retarded. Between t4 and t5, theexhaust pressure increases and the crankcase pressure is now less thanthe exhaust pressure by at least the threshold pressure. As shown, boostis still inactive and as a result, the wastegate may not be adjusted toadjust the exhaust gas pressure. However, as described above, if boostis active and the difference between the crankcase pressure and theexhaust pressure is less than the threshold pressure, then the wastegatemay be moved to a more closed position to increase exhaust pressure.

At t5, the vehicle may begin an extended driving operation. For example,between t5 and t6, the vehicle may drive 30,000 miles.

At t6, the vehicle is not reversing. The imaging device is imagingexhaust gas. Boost is inactive. Between t6 and t7, the images of theexhaust gas may be analyzed and it may be determined that the exhaustgas is not blue. As such, oil may not be leaking during non-boostedengine conditions.

At t7, boost may be active. The imaging device may capture one or moreimages of the exhaust gas, wherein the images may be analyzed for anamount of blue. The amount of blue in the exhaust gas images may exceedthe threshold amount and it may be determined that the exhaust gas isblue. As such, oil may be leaking into the exhaust gas during boostedengine conditions. The indicator lamp may be activated. After t7, theindicator lamp may remain active until one or more of the amount of bluein the exhaust gas is decreased and the vehicle is serviced to removethe oil leak. Additionally or alternatively, one or more engineoperating parameters may be adjusted in response to the exhaust gasbeing blue. For example, since the leak is during only boostedconditions, the turbo may be deactivated and only non-boosted engineoperating conditions may be utilized until the leak is removed.Additionally or alternatively, boost may decrease in response to theexhaust gas being blue.

In this way, an imaging device may be utilized for separate functionsduring different conditions of a vehicle. For example, imaging devicemay be a reverse camera, wherein the reverse camera projects asurrounding area to a vehicle operator during a reverse engine conditionand where the reverse camera captures exhaust gas images outside of thereverse condition. The technical effect of imaging exhaust gas is todetermine an amount of blue in the exhaust gas smoke, where the amountof blue may correspond to an oil leak. As such, based on engineconditions during the exhaust gas imaging, including cold-start, boost,tip-in, non-boost, and the like, it may be predicted from where the oilleak is occurring and engine operating parameters may be adjustedaccordingly. Additionally, by utilizing an imaging device alreadyarranged on the vehicle, manufacturing costs may be reduced.

A method comprising operating a reverse camera outside of a reversedriving condition, capturing one or more images of exhaust gas, anddetermining an amount of blue in the exhaust gas. A first example of themethod further includes where the reverse camera captures a firstsurrounding area during the reverse driving condition, wherein the firstsurrounding area includes an area between 0.5 to 5 meters of a rear of avehicle. A second example of the method, optionally including the firstexample, further includes where the reverse camera captures a secondsurrounding area outside of the reverse driving condition, wherein thesecond surrounding area includes an area within 0.5 meters of a rear ofa vehicle. A third example of the method, optionally including the firstand/or second examples, further includes where the second surroundingarea further includes one or more tailpipes and exhaust gas emittingtherefrom. A fourth example of the method, optionally including one ormore of the first through third examples, further includes where thedetermining further comprises comparing the amount of blue to athreshold amount of blue, wherein the threshold amount of blue isempirically determined. The operating includes one or more of actuatingand refocusing the reverse camera. A fifth example of the method,optionally including one or more of the first through fourth examples,further includes where reverse camera comprises a servomotor configuredto actuate the camera 360° within a fixed plane. A sixth example of themethod, optionally including one or more of the first through fifthexamples, further includes where the capturing further includescapturing images of exhaust gas during boosted and non-boosted engineconditions, wherein the amount of blue in the exhaust gas is comparedbetween the boost and non-boosted engine conditions.

A system comprising an engine configured to propel a vehicle, an imagingdevice arranged at a rear end of the vehicle, the rear end furthercomprising one or more tailpipes configured to emit exhaust gas of theengine to an ambient atmosphere, and a controller comprising instructionstored on non-transitory memory thereof that when executed enable thecontroller to capture images of the one or more tailpipes and exhaustgas during boost and non-boosted engine condition and determine anamount of blue in the images. A first example of the system furtherincludes where the controller being enabled to compare the amount ofblue to a threshold amount of blue, and where an oil leak is present ifthe amount of blue is greater than the threshold amount of blue. Asecond example of the system, optionally including the first example,further includes where oil is leaking during both the boosted andnon-boosted engine conditions if the amount of blue is greater than thethreshold amount of blue for images of both the boosted and non-boostedengine conditions. A third example of the system, optionally includingthe first and/or second examples, further includes where oil is leakingduring only the boosted engine condition if the amount of blue in theimage for the boosted engine condition is greater than the thresholdamount and if the amount of blue in the image for the non-boosted enginecondition is less than or equal to the threshold amount. A fourthexample of the system, optionally including one or more of the firstthrough third examples, further includes where oil is leaking duringonly the non-boosted engine condition if the amount of blue in the imagefor the non-boosted engine condition is greater than the thresholdamount and if the amount of blue in the image for the boosted enginecondition is less than or equal to the threshold amount. A fifth exampleof the system, optionally including one or more of the first throughfourth examples, further includes where the imaging device is adjustedby a servomotor, the servomotor configured to direct the imaging devicetoward the one or more tailpipes. A sixth example of the system,optionally including one or more of the first through fifth examples,further includes where there are two tailpipes, and where the servomotoroscillates the camera to a first and a second of the tailpipes.

A method comprising determining an oil leak via analyzing images ofexhaust gas during boosted and non-boosted engine condition captured bya reverse camera outside of a reverse driving condition and adjusting atleast one engine operating parameters in response to the oil leak. Afirst example of the method, further includes where the reverse drivingcondition includes a rear gear being selected and a vehicle beingpropelled in a reverse direction, wherein the reverse direction isvisible via the reverse camera. A second example of the method,optionally including the first example, further includes wheredisplaying images of exhaust gas in response to the oil leak, thedisplaying including displaying a live feed of the reverse camerarecording exhaust gas flowing out of one or more tailpipes. A thirdexample of the method, optionally including the first and/or secondexamples, further includes where the adjusting includes adjusting aboost pressure in response to the oil leak corresponding to the boostedengine condition. A fourth example of the method, optionally includingone or more of the first through third examples, further includes wherethe adjusting includes activating an indicator lamp.

A method comprising determining an oil leak via analyzing an exhaust gascolor and adjusting at least one engine operating parameter in responseto the oil leak and a pressure of a crankcase being within a thresholdof an exhaust gas pressure. A first example of the method furtherincludes where the oil leak is determined outside of a cold-start duringa naturally aspirated engine operating condition. A second example ofthe method, optionally including the first example, further includeswhere the oil leak is determined during a boosted engine operatingcondition. A third example of the method, optionally including the firstand/or second examples, further includes where the at least one engineoperating parameter includes adjusting an exhaust valve timing, whereinthe exhaust valve timing is retarded and where the exhaust valve timingis increasingly retarded in response to a difference between the exhaustgas pressure and the pressure of the crankcase decreasing. A fourthexample of the method, optionally including one or more of the firstthrough third examples, further includes where the at least one engineoperating parameter includes adjusting an exhaust tuning valve position,wherein the exhaust tuning valve is moved to a more closed position, andwhere the exhaust tuning valve is increasingly closed in response to adifference between the exhaust gas pressure and the pressure of thecrankcase decreasing. A fifth example of the method, optionallyincluding one or more of the first through fourth examples, furtherincludes where the at least one engine operating parameter includesadjusting a spark timing, wherein the spark timing is retarded, andwhere the spark timing is increasingly retarded in response to adifference between the exhaust gas pressure and the pressure of thecrankcase decreasing.

A method comprising determining oil is leaking from a crankcase to acombustion chamber via analyzing exhaust gas outside of a cold-startduring a non-boosted engine condition and retarding one or more of aspark timing and exhaust valve timing based on a difference between anexhaust gas pressure and a pressure of the crankcase. A first example ofthe method further includes where the spark timing is increasinglyretarded as the pressure of the crankcase approaches the exhaust gaspressure. A second example of the method, optionally including the firstexample further includes where the exhaust valve timing is increasinglyretarded as the pressure of the crankcase approaches the exhaust gaspressure. A third example of the method, optionally including the firstand/or second examples, further includes where adjusting a position ofan exhaust tuning valve arranged between a turbine and an emissioncontrol within an exhaust passage. A fourth example of the method,optionally including one or more of the first through third examples,further includes where the position of the exhaust tuning valve is moreclosed as the pressure of the crankcase approaches the exhaust gaspressure. A fifth example of the method, optionally including one ormore of the first through fourth examples, further includes where theexhaust tuning valve is configured to obstruct at least a portion of theexhaust passage.

A system comprising a multi-cylinder engine comprising a turbochargerhaving a compressor arranged in an intake passage and a turbine arrangedin an exhaust passage, an exhaust tuning valve arranged in the exhaustpassage between the turbine and an emission control device, an imagingdevice arranged at a rear of a vehicle, where the imaging devicevisualizes an area exterior to the vehicle, and a controller withcomputer readable instructions stored on non-transitory memory thereofthat when executed enable the controller to visualize exhaust gas viathe imaging device during boosted and non-boosted engine conditions,analyze an amount of blue in the exhaust gas, determine an oil leak whenthe amount of blue is greater than a threshold amount of blue, andadjust one or more of a spark timing, an exhaust valve timing, and aposition of the exhaust tuning valve. A first example of the systemfurther includes where exhaust gas is visualized during combustingevents of the multi-cylinder engine. A second example of the system,optionally including the first example, further includes where theimaging device is arranged above a tailpipe. A third example of thesystem, optionally including the first and/or second examples, furtherincludes where a number of imaging devices is equal to a number oftailpipes. A fourth example of the system, optionally including one ormore of the first through third examples, further includes where theamount of blue increases as an amount of oil in the exhaust gasincreases. A fifth example of the system, optionally including one ormore of the first through fourth examples, further includes wheredetermining oil is not leaking in response to the amount of blue beingless than or equal to the threshold amount. A sixth example of thesystem, optionally including one or more of the first through fifthexamples, further includes where spark timing, exhaust valve timing, andthe position of the exhaust tuning valve are adjusted in response to acrankcase pressure being within a threshold of an exhaust gas pressurewhen oil is not leaking to mitigate a likelihood of a future oil leakdeveloping. A seventh example of the system, optionally including one ormore of the first through sixth examples, further includes where theimaging device is a camera or video recorder.

Note that the example control and estimation routines included hereincan be used with various engine and/or vehicle system configurations.The control methods and routines disclosed herein may be stored asexecutable instructions in non-transitory memory and may be carried outby the control system including the controller in combination with thevarious sensors, actuators, and other engine hardware. The specificroutines described herein may represent one or more of any number ofprocessing strategies such as event-driven, interrupt-driven,multi-tasking, multi-threading, and the like. As such, various actions,operations, and/or functions illustrated may be performed in thesequence illustrated, in parallel, or in some cases omitted. Likewise,the order of processing is not necessarily required to achieve thefeatures and advantages of the example embodiments described herein, butis provided for ease of illustration and description. One or more of theillustrated actions, operations and/or functions may be repeatedlyperformed depending on the particular strategy being used. Further, thedescribed actions, operations and/or functions may graphically representcode to be programmed into non-transitory memory of the computerreadable storage medium in the engine control system, where thedescribed actions are carried out by executing the instructions in asystem including the various engine hardware components in combinationwith the electronic controller.

It will be appreciated that the configurations and routines disclosedherein are exemplary in nature, and that these specific embodiments arenot to be considered in a limiting sense, because numerous variationsare possible. For example, the above technology can be applied to V-6,I-4, I-6, V-12, opposed 4, and other engine types. The subject matter ofthe present disclosure includes all novel and non-obvious combinationsand sub-combinations of the various systems and configurations, andother features, functions, and/or properties disclosed herein.

The following claims particularly point out certain combinations andsub-combinations regarded as novel and non-obvious. These claims mayrefer to “an” element or “a first” element or the equivalent thereof.Such claims should be understood to include incorporation of one or moresuch elements, neither requiring nor excluding two or more suchelements. Other combinations and sub-combinations of the disclosedfeatures, functions, elements, and/or properties may be claimed throughamendment of the present claims or through presentation of new claims inthis or a related application. Such claims, whether broader, narrower,equal, or different in scope to the original claims, also are regardedas included within the subject matter of the present disclosure.

1. A method comprising: operating a reverse camera in a non-reversedriving condition; while capturing images of exhaust gas; and adjustingengine operation in response to an amount of a specified color range inthe exhaust gas images.
 2. The method of claim 1, wherein the reversecamera captures a first surrounding area during the non-reverse drivingcondition, wherein the first surrounding area includes an area between0.5 to 5 meters of a rear of a vehicle.
 3. The method of claim 1,wherein the reverse camera captures a second surrounding area outside ofthe non-reverse driving condition, wherein the second surrounding areaincludes an area within 0.5 meters of a rear of a vehicle.
 4. The methodof claim 1, wherein the second surrounding area further includes one ormore tailpipes and exhaust gas emitting therefrom.
 5. The method ofclaim 1, wherein the specified color range includes a visible blue colorrange, and the determining further comprises comparing the amount ofblue in the captured image to a non-zero threshold amount of blue. 6.The method of claim 1, wherein the operating includes one or more ofactuating and refocusing the reverse camera.
 7. The method of claim 6,wherein the reverse camera comprises a servomotor configured to actuatethe camera 360° within a fixed plane, and wherein the vehicle is anautonomous vehicle.
 8. The method of claim 1, wherein the capturingfurther includes capturing images of exhaust gas during boosted andnon-boosted engine conditions, wherein the amount of the specified lightcolor in the exhaust gas is compared between the boosted and non-boostedengine conditions, and where an oil leak is determined to be leaking inone or more of the boosted and non-boosted engine conditions, furthercomprising decreasing a turbocharger output in response to an oil leakbeing determined during the boosted engine condition, and where anexhaust valve timing or a spark timing is retarded in response to an oilleak being determined during the non-boosted engine condition.
 9. Asystem comprising: an engine configured to propel a vehicle; an imagingdevice arranged at a rear end of the vehicle, the rear end furthercomprising one or more tailpipes configured to emit exhaust gas of theengine to an ambient atmosphere; and a controller comprising instructionstored on non-transitory memory thereof that when executed enable thecontroller to: capture images of the one or more tailpipes and exhaustgas during boost and non-boosted engine condition; and determine anamount of blue in the images and indicate degradation of engine oil bygenerating an indication to a vehicle operator.
 10. The system of claim9, further comprising the controller being enabled to compare the amountof blue to a threshold amount of blue, and where an oil leak is presentif the amount of blue is greater than the threshold amount of blue. 11.The system of claim 10, wherein oil is determined to be leaking duringboth the boosted and non-boosted engine conditions if the amount of blueis greater than the threshold amount of blue for images of both theboosted and non-boosted engine conditions.
 12. The system of claim 10,wherein oil is leaking during only the boosted engine condition if theamount of blue in the image for the boosted engine condition is greaterthan the threshold amount and if the amount of blue in the image for thenon-boosted engine condition is less than or equal to the thresholdamount, and where a turbocharger output is decreased in response to thedetermined oil leak during the boosted engine condition.
 13. The systemof claim 10, wherein oil is leaking during only the non-boosted enginecondition if the amount of blue in the image for the non-boosted enginecondition is greater than the threshold amount and if the amount of bluein the image for the boosted engine condition is less than or equal tothe threshold amount, and where an in-cylinder pressure is increased byretarding one or more of a spark timing and exhaust valve timing. 14.The system of claim 10, wherein the imaging device is adjusted by aservomotor, the servomotor configured to direct the imaging devicetoward the one or more tailpipes.
 15. The system of claim 14, whereinthere are two tailpipes, and where the servomotor oscillates the camerato a first and a second of the tailpipes.
 16. A method comprising:analyzing images of exhaust gas for an oil leak during boosted andnon-boosted engine condition captured by a reverse camera during anon-reverse driving condition; and adjusting at least one engineoperating parameters in response to the oil leak.
 17. The method ofclaim 16, wherein a reverse driving condition includes a rear gear beingselected and a vehicle being propelled in a reverse direction, whereinthe reverse direction is visible via the reverse camera, and where thenon-reverse driving condition include the rear gear not being selected.18. The method of claim 16, further comprising displaying images ofexhaust gas in response to the oil leak, the displaying includingdisplaying a live feed of the reverse camera recording exhaust gasflowing out of one or more tailpipes.
 19. The method of claim 16,wherein the adjusting includes adjusting a boost pressure in response tothe oil leak corresponding to the boosted engine condition.
 20. Themethod of claim 16, wherein the adjusting includes activating anindicator on a vehicle display, and where the analyzing includesanalyzing imaged during both boosted and non-boosted conditions, theindication based on whether the leak is indicated during both boostedand non-boosted conditions, and based on whether the leak is indicatedonly during boosted conditions.